A seemingly unsolvable Broadband problem?!

[IanSaunders1]

I come here in the search of experts! 

I inherited a previous tenant's broadband service which ran without issues from January to May.  From May onwards I was experiencing outages from lunchtime (12-1pm) to early evening (6-8pm).  It wasn't my service so I couldn't request support so had to live with it until I could finally take over the line.  I did this 2 weeks ago signing up for BT Fibre 2.  However, the issue continues...

Thinking back, I noticed a pattern that issues/outages only occur on hot, sunny days from lunchtime onwards (hottest part of the day).  I understand that correlation is not causation, but it's going beyond coincidence now.  I've searched the forums and this is usually connected to the router getting too hot.  I've had 3 different routers which are never in direct sunlight so that's unlikely to be the issue.  I've had a couple of engineer visits but the problem persists.  When I try to explain the link with hot, sunny weather, they give me the same blank response an alien abductee would probably receive!

On a hot, sunny day, BT detected a high resistance fault between the cabinet and my house.  This has still not been fixed despite me being told that various tests have been successfully performed (probably on cloudy days!)  My questions to any expert on here are:

1.  Can a high resistance fault of this nature be corrected without implementing a fix?

2. Does anyone have any explanation as to why this fault only appears to manifest under hot, sunny conditions?

Yours hopefully,

Ian

[licquorice]

A high resistance fault is a corroded wire or joint and can only be fixed by either replacing the wire or joint

It is quite possible that expansion and contraction with variation of temperature could affect the fault.

[IanSaunders1]

I appreciate your speedy, succinct response.  I now feel suitably armed to tackle BT about this.  I suspected that part of the delay is that Openreach are not keen to climb ladders or descend manholes to fix cables.

[spacepilot]

check or reset your modem / router, as some can be set to block access at certain times, so the kids will come and get food... and put away their devices

https://www.bt.com/help/user-guides/bt-whole-home-wi-fi/what-are-access-controls-and-how-do-i-turn-i...

[pippincp]

@spacepilotUnfortunately your reply has nothing to do with @IanSaunders1 problem. Both @licquorice and I know what the problem is and how  it would be fixed.

A high resistant joint could be anywhere between the OP and the cabinet. A skillful engineer would check  them and repair or replace if needed.

[IanSaunders1]

My temporary clarity and optimism has taken a blow!

The Openreach engineer has just visited.  He said that since my network fault on Sun/Mon, my speed had been temporarily capped (this can be an automated process).  This was largely irrelevant to me as the service became unusable with numerous disconnects.  He has now removed this as my service is fine today (a cloudy day here so as expected).  He has also updated the NTE.  

He isn't able to do anything else as his checks today do not detect any fault.  He can't provide any explanation for the issues on Sunday and Monday.  When I mentioned that I had been told previously that there was a high resistance fault (which to my knowledge has never been fixed), he said that this fault would be detectable every day and therefore his tests today would still reveal it.  Is this true or can it's detection be intermittent? 

He then said that sometimes BT's diagnosis of a fault can differ to that of Openreach!  In other words, I've no got no idea whether there ever was a high resistance fault, and I just have to wait for the next spell of better weather to go through the same cycle once more.   

Unless there's a sustained heatwave, I think we're heading back to unsolvable!